Field of the Invention
This invention relates to the field of gene therapy for the treatment of cancer. In one embodiment, the invention relates to the engineering of dendritic cells to conditionally express interleukin-12 (IL-12) and use of the cells for therapeutics. In another embodiment, the invention relates to the engineering of dendritic cells to conditionally express interleukin-12 (IL-12) and/or interferon-alpha (IFN-alpha) and use of the cells for therapeutics.
Background
Various patents, patent applications, and publications are cited herein, the disclosures of which are incorporated by reference in their entireties. However, the citation of any reference herein should not be construed as an admission that such reference is available as “Prior Art” to the present application.
Interleukin-12 (IL-12) is a member of the type I cytokine family involved in contributing to a number of biological processes including, but not limited to, protective immune response and suppression of tumorigenesis (Abdi et al., 2006; Adorini, 1999; Adorini, 2001; Adorini et al., 2002; Adorini et al., 1996; Akhtar et al., 2004; Akiyama et al., 2000; Al-Mohanna et al., 2002; Aliberti et al., 1996; Allavena et al., 1994; Alli and Khar, 2004; Aizona et al., 1996; Amemiya et al., 2006; Araujo et al., 2001; Arulanandam et al., 1999; Athie et al., 2000; Athie-Morales et al., 2004; Bertagnolli et al., 1992; Bhardwaj et al., 1996; Biedermann et al., 2006; Brunda and Gately, 1994; Buchanan et al., 1995; Romani et al., 1997; Rothe et al., 1996; Satoskar et al., 2000; Schopf et al., 1999; Thomas et al., 2000; Tsung et al., 1997; Wolf et al., 1994; Yuminamochi et al., 2007). A growing body of evidence suggests that IL-12 may be a promising target to control human diseases (e.g., cancer).
Despite the fact that IL-12 remains promising as a cancer therapeutic agent based on its potent supportive activity on Type-1 anti-tumor NK cells, CD4+ T cells and CD8+ T cells (Trinchieri, 2003), the reported toxicity of recombinant human IL-12 (rhIL-12) in patients (Atkins et al., 1997), together with limited sources of GMP-grade rhIL-12 for clinical application, have prevented successful IL-12-based therapeutic approaches. Thus it seems reasonable that gene therapy approaches may represent safer, more tenable treatment options. Indeed, phase I clinical trials implementing intra- or peri-tumoral delivery of recombinant viral- (Sangro et al., 2004; Triozzi et al., 2005) or plasmid-based IL-12 cDNA (Heinzerling et al., 2005), or IL-12 gene modified autologous fibroblasts (Kang et al., 2001) have been found safe and well-tolerated.
However, objective clinical responses in patients with melanoma or a diverse range of carcinomas receiving these gene therapies have been rare, variable, transient and largely focused at the site of treatment (Heinzerling et al., 2005; Kang et al., 2001; Sangro et al., 2004; Triozzi et al., 2005). In cases where disease resolution was partial or complete, increased frequencies of tumor-infiltrating lymphocytes (Heinzerling et al., 2005; Sangro et al., 2004) and elevated levels of circulating tumor-specific CD8+ T cells (Heinzerling et al., 2005) have been noted, consistent with the improved cross-priming of antigen-specific T cells in these patients.
In addition, there raised several residual concerns, e.g., unanticipated toxicities associated with DC-based IL-12 gene therapy and potential IL-12-dependent limitations in therapeutic DC.IL12 migration after intratumoral administration. Furthermore, there are further concerns regarding a timing of IL-12 production in transduced DC most important for therapeutic efficacy (Murphy et al, 2005)
Since the cross-priming of specific T cells is best accomplished by dendritic cells (DC) that serve as a natural but regulated source of IL-12 (Berard et al., 2000), recent reports of the superior pre-clinical efficacy of DC-based IL-12 gene therapy have been of great interest (Satoh et al., 2002; Tatsumi et al., 2003; Yamanaka et al., 2002). For example, it was shown that intratumoral (i.t.) injection of DC engineered to produce IL-12p70 (via recombinant adenovirus infection) results in the dramatically improved cross-priming of a broadly-reactive, tumor-specific CD8+ T cell repertoire in concert with tumor rejection in murine models (Tatsumi et al., 2003). Given the previous use of a recombinant adenovirus encoding mIL-12 under a CMV-based promoter (rAd.cIL12, (Tatsumi et al., 2003)), engineered DC production of IL-12 was constitutive, hence the immunologic impact of this cytokine early within the tumor lesion and later within tumor-draining lymph nodes could not be resolved with regards to therapeutic outcome. Thus, a need exists for DC engineered for conditional expression of IL-12. The invention provides a promising therapeutic outcome for the use of such cells.